WIFI (Wireless Fidelity), a wireless network access technology, is the most widely used wireless network transmission technology. With constant development of this technology, smart terminals capable of connecting a network through WIFI, such as tablet computers and smart phones, are becoming increasingly popular, and WIFI hotspots that enable smart terminals to access a network wirelessly are also increasing such that the smart terminals can access a network wirelessly through the WIFI hotspots. However, the wireless access of a smart terminal to the network depends on the availability of a WIFI hotspot, which cause a certain limitation. To be specific, if no WIFI is available at a place, a smart terminal cannot access the network wirelessly.